Rifling cutter



April ll, 1.944. F. o. HOAGLAND RIFLING CUTTER Filed May 5.. 1942wifi/V701@ JZ 0. 1700 W4 NMBN Uwe/ffy Patented Apr. 11, 1944 UNITEDSTATES PATENT OFFICE RIFLING CUTTER y Frank O. Hoagland, West Hartford,Conn., as-

sig'nor to Niles-Bement-Pond Compannwest Hartford, Conn., a corporationof New Jersey Application May 5, 1942, Serial N0. 441,829

4 Claims. `('Cl. 9028.1)

This invention relates to rifling cutters and particularly to a doubleended cutter for use in arifling head for a standard form of gun barrelrifling machine. v i

An object of the present invention is to provide an improved form ofrifling cutter having cutting surfaces at its opposite ends disposed inopposed relation to each other, the cutter being pivotally mounted sothat the cutting surfaces at its opposite ends may eiect a cuttingoperation in each direction of reciprocation of the head through the gunbore being rifled.

Another object of the invention is to provide a pivotal support for thecutter preferably disposed centrally of the cutter, there being arcuatesurfaces at the ends of an elongated central transverse opening in thecutter for engagement with a transverse pin xed in the head and formedto engage these arcuate surfaces and permitting limited pivotal movementof the cutter.

With the above and other objects in View the invention includes thefeatures of construction and operation set forth in the followingspecification and illustrated in the accompanying drawing.

In the accompanying drawing annexed hereto and forming a part .of thisspecification, I have shown the invention embodied in a rifling headsimilar to that disclosed and claimed in my copending application SerialNo. 390,582, flled April 26, 1941, now Patent No. 2,230,584, grantedSeptember 28, 1943, and entitled Tool head for riiiing machine. It willbe understood, however, that the invention can be otherwise embodied andthat the drawing is not to be construed as defining or limiting thescope of the invention, the claims appended to this specification beingrelied upon for that purpose.

In the drawing:

Figure 1 is a central longitudinal sectional View of a riling tool headshowing the cutter forming the subject matter of the .present inventionin position therein,

Fig. 2 is an inverted plan view of the cutter shown in Fig. 1 upon anenlarged scale.

Fig. 3 is a side elevation of the tool corresponding to that shown inFig. 2.

Figs. 4 and 5 are cross sectional views of the cutter and head taken onthe planes of lines 4-4 and 5-5 respectively and on enlarged 50 scales;and

Fig. 6 is an enlarged side elevation of the cutter adjacent its pivotalopening showing the relation of the pin to the walls of the openingsupporting the cutter and permitting it to oscillate.

In the above-mentioned drawing there has been shown but one embodimentof the invention which is now deemed preferable, but it is to beunderstood that changes and modications may be made within the scope ofthe appended claims Without departing from the spirit of the inven-Ition.

It has heretofore been the practice to form the rifling grooves withinthe bore of a gun barrel by reciprocating a rifling tool therethroughand adjusting its cutting edge or edges so that it will successively cutdeeperinto the riiiing grooves after each complete indexing of thebarrel. In cutters as heretofore made the cutting action has beenrestricted to movement of the tool through .the gun barrel in onedirection only and it is a Referring more in detail tothe figures vof.thedrawing, there is shown a rifling tool head having a sleeve I0 and atransverse pin II extend ing therethrough presently to be more `fully.de. scribed. Slidably disposed within the rifling sleeve I0 is a memberI2 having oblique surfaces I3 forming the terminal surfaces of arecessed portion similar to the corresponding member in theabove-mentioned copending application. Supported centrally upon thetransverse pin II is the cutter I4 forming the subject matter of thepresent invention. At opposite ends of the cutter I4 are cuttingsurfaces 9 obliquely disposed and facing in opposite directions. Thiscutter I4 in its preferred embodiment, as shown, has a centraltransverse opening I5 suitably elongated and having arcuate surfaces I6at its opposite ends. The upper and lower surfaces of this opening areflat and parallel to each other and the end walls form the mid portionsof a cylinder having a diameter equal to the length of the opening. Thepin II upon which the cutter I4 is supported is suitably elongated tot'the opening and has arcuate or cylindrical surfaces at its oppositeends contacting the end walls of the cutter opening I6. The pin II hasits upper and lower or side surfaces I'I suitably tapered from itscentral toward its end portions, the central portion of the pin havingthe greatest thickness and corresponding to the Width of the opening inthe cutter. By means of this pin II the cutter I4 is supported againstvertical displacement by the be transversely crowned slightly to permitaci"` i justrnent as indicated in Fig. 5.

In my copending application the operation of the slidable member l2Within;` the sleeve/f1.0" to alternately support the cutterlll' in.voperative position for cutting in each direction has' been described sothat further description; of. thisrinember and its adjustable limits ofmovement will l not be necessary, It will suiiice to state that witheach reversal of movement, of thefriling headthe slidable member i2 isforced to its opposite Vaxial position whichzcauses the cutter- IllVto.y pivot aboutn itsk central supporting pin Hf., The cutting surfacesat. one` :end of ther cutter will therefore. be advanced'.to` operativeposition lto out the riflingl grooves in each direction of movement ofthe.v riing head.

Itwill benoteny that in; Fig; 3 the front cutting surfaces. 9i at: theopposite ends: of the cutter; i4 are: disposed obliquely relative to.the length of the cutter but are in alinement. axially of the; cutter'as. disposed inthe cutting head. Also the cutting.r teeth extendobliquely in conformitywith and their oblique angley corresponds to thelead of the riing., Itv has-beeny explained in my copending-applicationthat the cutting surfaces at oneend, of the cutterv when, moving in onedirectiony will cut. intoA one of the rifling grooves while. movement ofthe cutter in the opposite direction will enter an adjacent groove. Asthe grooves in the bore of the gun barrel are disposed uniformly aboutthe periphery of the bore, the relative disposition of the cuttingsurfaces at the oppositeV ends and their obli'queangl'eare critical andare made to con-formI tothe requirements.` of they particular gunlbarrel' being ri'fled.

I claim:

l. A cutter for riiling tool heads having cutting surfaces at itsopposite ends disposed obliquely and in opposed relation to each otherfor cutting in opposite directions of movement of said tool, said cutterhaving a central elongated opening extending transversely therethrough,said opening having opposed arcuate end surfaces; forming meanspermitting limited pivotal movements of said tool Within a rifling headin opposite directions. 2'. Acutter for rifling tool heads havingcutting surfaces at its opposite ends disposed in opposed relationtoeachotlierfor cutting in opposite directionsdof movement of said tool, saidcutter having a central elongated opening extending transverselytherethrough, said opening having opposed arcuate end surfaces and planeparallel top 'and' bottom surfaces forming means for positioning: saidtool Within a. rifling headand perhead:V for. liimted pivotalmovementtherein.

3-. A cutter for-riding tool heads having obliquely positioned cuttingsurfaces at its opposite ends disposed in opposedy relation to eachotherfor cutting inopposite directionsI of movement ofl saidtoolgl said-`cutter having a central. elongated; opening extendingl transverselytherethrough having plane parallel top and loottomV surfaces and opposedarcuate. end surfaces for mounting` said tool in position` Within arifling head for liimted pivotalmovement. therein.

4. Acutter for riing, tool headshaving cutting surfaces at` its oppositeends disposed in opposed;

relation to; each. other for cutting in opposite directions of` movementof said tool, said cutterl having; an central` elongated opening;extending transversely through said tool, said opening. hav- FRANK `O.HOAGLAND.

CERTIFICATE OF CORRECTION.

Patent No. 2,5Lp6,581 April 11, 19ML.

FRANK o. HoAeLAND.v

It is. hereby certified that error appears in the printed specificationof the above numbered patent requiring correction as follows: Page 2,second column, lines 2O and 21, claim 2, for "perhead for liimted" read'Line 5l, claim 5, for "liimted" read limited-- ith this correctiontheren the Patent Of- --permitting lmited;

and that the said Letters Patent should be read w in that the same mayconform to the record of the oase i.

Signed and sealed this 50th day of May, A. D. 19141;.

Leslie Frazer (Seal) Acting Commissioner of Patents.

